It is known to use a bending device having an approximately circular-cylindrical bending template which is displaceable in the direction of its axis in a guide block, and a bending tool eccentrically disposed on a bending plate and pivotable around the bending template, the guide block located opposite the bending plate constituting a support surface for the wire to be bent, and where a device for welding the cross wire end pieces which are bent back to the longitudinal edge wires and, if desired, a device for beveling the loops are preferably disposed downstream of the bending device.
A bending device is known from U.S. Pat. No. 4,526,025, to which Austrian Patent AT-PS 377 713 corresponds, wherein the approximately circular-cylindrical bending template is axially displaceable between a working position, in which the front faces of the bending template and the bending plate touch, and a rest position, in which these two front faces delimit between each other a penetrating gap for the cross wire end piece to be bent. The front face of the bending template and the support surface of the guide block are located opposite the front face of the bending plate and during bending enclose the cross wire end piece to be bent, so that during bending the cross wire end piece can be supported on the one hand on the support surface of the guide block and on the other on the front face of the bending plate, by means of which shifting of the cross wire end piece out of the plane of the cross wires is prevented. In this bending device it is disadvantageous that, although in its initial position the bending tool can keep the feed path for the cross wire end piece bent into a loop free, an unbent, straight cross wire end piece cannot pass the bending device. It is furthermore possible to bend the cross wire end pieces of a wire lattice mat into loops in only one direction with the aid of this bending device.
A bending device for bending of hoops from rod-shaped material is known from German Patent Publication DE-C2 25 14 187. This bending device has a support frame which can be moved back and forth perpendicularly to the direction of the material feed, on which are disposed a rotatable bending plate provided with an eccentric bending block and a guide peg for the material to be bent, which can be moved back and forth in relation to the bending plate and is disposed almost in the center axis of the bending plate, but is not rotatable. Both the guide peg and the bending plate are located on the same side of the material to be bent. This bending device has the disadvantage that a support surface for the wire to bent is lacking on the side of the support surface located opposite the bending plate, so that during bending of cross wire end pieces of wire lattice mats into loops it is not possible to prevent the bent cross wire end sections from shifting out of the plane of the cross wires.